260 COMPOSITiE. Pluchea. 



Subtribe 3. Tarchonanthej;, Less. — Heads discoid, never radiate, di- 

 CEcious or hetero2;amous ; the fertile flowers tubular-filiform, mostly truncate, 

 when lieterogamous with the perfect or staminate flowers in the centre. 

 Receptacle sometimes chafl}'. Anthers caudate at the base. — Leaves 

 alternate. 



COXSPECTUS OF THE GENERA. 



* Pappus of the sterile and fertile flou-ers similar, capillary. 



58. Pluchea. Involucre persistent. Heads in compound corymbs. 



59. Pterocaulon. Involucre deciduous. Heads spicate. Leaves decuiTcnt. 



* * Pappus of the sterile and fertile floioers none. Receptacle flat or conical. 

 +- Flowers all fertile. 



60. Calymmandra. Achenia of the perfect flowers only enclosed by the chaff. 



•f- +- Staminate flowers few, sterile. 



61. Filagiko^sis. Fertile flowers numerous, in the axils of narrow equal chaff. 



62. Diaperia. Fertile flowers 8-12. in the axils of broad unequal concave chaff. 

 53. MiCROPrs. Fertile flowers 5-7, enclosed in rigid gibbous scales. 



64. Psilocarphus. Fertile flowers numerous, enclosed in membranous chaff. 



* * * Pappus of the sterile flou-crs of few bristles. Receptade columnar. 



65. Stylocline. Achenia numerous, enclosed in the saccate keel of the broad 



chaff. 



68. PLUCHEA. Cass. bull, philom. 1817, p. 31 ; DC. prodr. 5. p. 449. 



Stylimnus & Gynema, Raf (1819.)— Leptogyne, Ell. (18-24.) 



Heads many-flowered; the central flowers mostly perfect, but sterile ; the 

 others filiform, pistillate, in many series. Involucre imbricated. Recepta- 

 cle flat, mostly naked. Corolla of the fertile flowers truncate, or mi- 

 nutely 2-3-toothed ; of the sterile dilated and 5-cleft at the summit. Anthers 

 bicaudate. Style in the central flowers entire or minutely 2-toothed. Ache- 

 nia somewhat cylindrical, angled or grooved. Pappus capillary, in a_single 

 series, slightly scabrous. — Herbs, or rarely suffrutescent plants (mostly sub- 

 tropical), glandular, emitting a strong and somewhat disagreeable odor. 

 Leaves oval or oblong, serrate. Heads in compound corymbs. Flowers 

 mostly purplish. 



1. P. hifrons (DC.) : pubescent and slightly viscid ; leaves oval or lanceo- 

 late-oblong, somewhat cordate and clasping at the base, mucronately serru- 

 late, reticulate-veined, sprinkled with resinous globules ; heads in compact 

 fastigiate corymbs. — DC! j^^odr. 5. p. 451. Conyza hifrons, Linn. spec. 2. 

 p. 862 (excl. var. radiata) ; Pursh, fl. 2. p. 524 ; Ell. sk. 2. p. 322 ; Hook, 

 compan. to hot. mag. 1. p. 96. C. amplexicaulis, Michx.! fl. 2. p. 126. 

 /3. uliginosa, Pers., ex DC. Baccharis viscosa, Walt. ! car. p. 202. 



Wet places in the low country, from South Carolina! to Florida! and 



